The present invention relates to fluid flow channels, particularly to glass/silicon fluid flow columns and more particularly to a glass-silicon column capable of use with temperatures between room temperature to about 450xc2x0 C., having flow channels and an electrode embedded therein, and provided with a self-alignment silicon post and glass hole structure.
In the early 1980s, it was established that a thin piece of Corning 7740 boron silicate glass could be anodically bonded onto a silicon wafer. The glass-silicon assembly could withstand temperature variation between room temperature and about 450xc2x0 C. With etched structures between the bonded glass and silicon layers or plates, they have been utilized for various applications, including coolers for many different systems.
This glass-silicon bonded system has been used in many other applications, such as where temperature variation is quite small, such as, isotherm gas chromatography, or even with small temperature ramping; electrophoresis where the applied voltage is not extremely high, and multiple channel electrolytic flow for analyzing ions or biological cells. In the gas chromatography application, the temperature of the separation column located between glass and silicon wafers, cannot vary rapidly because of the poor thermal conductivity of the glass, but its fabrication is much easier and the user can see through the glass side in case there is a blockage. In the electrophoresis application, one can even use a second piece of the thin glass with etched columns between two pieces of glass in order to be used under high voltage. The silicon wafer in this case is used to achieve more uniform temperature under heating. In the multiple channel electrolytic flow application, one can design and include various electrode and/or optical waveguide for detection and control.
The present invention provides a glass-silicon column, which can be utilized in the various above-referenced application, as well as water cooler or fluid temperature control columns for applications such as injection lasers and integrated circuit chips. The silicon wafer or layer located on opposite sides of the column of the invention achieves more uniform temperature, particularly under heating. The silicon-glass-silicon column provides are large surface area, with an electrode embedded in the glass as a column heater, but can also function as a heater for anodic bonding of the silicon and glass members or plates.
It is an object of the present invention to provide a glass-silicon column.
A further object of the invention is to provide a glass-silicon column having outer silicon layers anodically bonded to at least one inner glass layer.
Another object of the invention is to provide a glass-silicon column with at least one fluid channel therein as well as an embedded electrode.
Another object of the invention is to provide a large area silicon-glass-silicon anodically bonded column having fluid channels formed therein and an electrode embedded therein.
Another object of the invention is to provide a large area silicon-glass-silicon column with a self alignment structure for the silicon and glass members.
Another object of the invention is to provide a silicon-glass-silicon column having an embedded electrode which can function for anodic bonding of the silicon and glass as well as a column heater.
Other objects and advantages of the present invention will become apparent from the following description and accompanying drawing. The invention involves a glass-silicon column which can withstand temperature variation between room temperature and about 450xc2x0 C. These variations in temperature do not cause a disruption of a large area bonding between the glass and silicon, such as between thin (10-20 Mil) Corning 7740 boron-silicate glass and a silicon wafer. The silicon wafer, in certain applications is used to achieve more uniform temperature under heating, such as by an electrode embedded in the glass. The glass-silicon column of this invention involves a large area silicon-glass-silicon column where the silicon and glass are anodically bonded. Also, the column includes an electrode which can be used for anodic bonding as well as a column heater. The silicon and glass components are provided with a self-alignment structure, such as a silicon post and a glass hole. The glass may composed of a plurality of anodically bonded layers.